ABSTRACT
Shale gas may be stored as free gas in natural fractures and intergranular porosity, as gas sorbed onto kerogen and clay particle surfaces, or as gas dissolved in kerogen and bitumen. The adsorbed gas accounted for 20% to 85% of total gas content in five United States shale formations. The adsorbed gas of Barnett shale account for 61% of the original geological reserve (Mavor et al. 2003). Antrim shale is based on adsorption shale gas, free gas accounted for only 25% to 30% of the total gas content (Martini et al. 2003). Chinese scholars also made exploratory study, Sichuan Basin Jiaoshiba area Wufeng formation-Longmaxi formation shale adsorbed gas content accounted for 35% to 47% of the total gas content (Guo et al. 2014); Sichuan Basin and its perighery Cambrian shale adsorbed gas content accounted for 4% to 75% of total gas content (Nie et al. 2011).
